Hydrogen re-embrittlement of coated steel can result in a considerable deterioration of the properties of coated steel. A deposition of individual hydrogen atoms in the lattice structure of the steel in this respect effects an increase in the pressure in the lattice matrix and results in a disadvantageous change in the steel brittleness. A hydrogen-induced crack formation of the steel can consequently result in this respect, whereby the properties with respect to strength associated with a steel in a normal case can no longer be maintained. Such a crack formation would in particular bring about devastating consequences in the field of aeronautics in which major components such as the main undercarriage, the transmission or bolts are produced from steel.
A re-embrittlement of a coated high-strength steel typically occurs as a result of corrosion. Atomic hydrogen is created in this respect at the surface of the high-strength steel and/or the coating, either by hydrogen corrosion or by a different chemical reaction. The atomic hydrogen partly diffuses into the material (=steel) before a combination into a non-diffusible H2 molecule takes place. The atomic hydrogen diffused into the material is deposited at lattice defects in the lattice structure of the steel and results in an embrittlement of the steel such that a brittle crack or a brittle fracture can occur due to the pressure increase associated therewith in the interior of the steel.